package january.test_1_31;

import java.util.Scanner;

public class TestMain2 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int m = scanner.nextInt();
        int n = scanner.nextInt();
        int[][] dp = new int[m + 2][n + 2];
        dp[0][1] = 0;
        dp[1][0] = 1;
        for(int i = 1; i < m + 2; i++) {
            for (int j = 1; j < n + 2; j++) {
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
            }
        }
        System.out.println(dp[n + 1][m + 1]);
    }
}
